Experimental and analytical properties of 0.2-μm-wide, end-on, multilayer, giant magnetoresistance, read head sensors

Abstract

Sensing elements which are 0.20 μm wide have been fabricated from giant magnetoresistance material that has four magnetic layers separated by 16–17 Å copper alloy layers. The material has a bulk magnetoresistive coefficient of 12%–15%, and when etched into the 0.2-μm-wide stripes, the stripe material has a shifted linear response range of about 8%, extending from −140 to +140 Oe, for example. Empirical models have been developed for both the bulk material and the stripe material. Using the stripe material model, a numerical analysis was performed for end-on, 0.2-μm-wide, read head sensors in a shielded read head with a 0.25 μm head gap. The analysis shows that with input fields of ±100 Oe from transitions, a peak to peak output of 0.85 mV can be achieved in the assumed read head structure with a 0.20-μm-wide tip. If a 0.25 μm flux gathering tip is used, the peak to peak output can be increased to 1.3 mV.